No abstract

Background Berberine (BBR) has been found to have antiobesity effects, and obesity can lead to adipose tissue degeneration. As a special adipose tissue, perivascular adipose tissue (PVAT) is closely related to vascular function and affects vasoconstriction and relaxation. What happens to PVAT in the early stages of diet-induced obesity and how BBR affects vascular function is the focus of our experimental study. Methods Sprague–Dawley rats were fed a high-fat diet (fat 34% kcal) for 4 weeks to simulate early obesity. Obese rats were treated with BBR (200 mg/kg) or metformin (MET, 100 mg/kg) by gavage for 2 weeks. The mesenteric arterioles were studied by atomic force microscopy (AFM). The force vs. time curves were observed and analysed to indicate vascular function. Nitric oxide (NO) and noradrenaline (NA) release was quantified using an organ bath with fluorescence assays and ELISA, respectively. Network pharmacology was used to analyse the overlapping targets related to BBR and obesity-related diseases, and the expression of NOS in mesenteric PVAT was further analysed with immunohistochemistry and real-time PCR. The serum inflammatory factor levels were tested. Results BBR significantly reduced the levels of blood glucose, blood lipids and inflammatory factors in serum. It also effectively improved abnormal mesenteric vasoconstriction and relaxation in obese rats. There was no significant change in mesenteric vascular structure, but NO production and eNOS expression were significantly increased in mesenteric PVAT (P < 0.01), and NA was decreased (P < 0.05) in obese rats. All these changes in the mesenteric arterioles and PVAT of obese rats were reversed by treatment with BBR and MET. Conclusions In diet-induced obesity in rats, the function of vasoconstriction and relaxation in mesenteric arterioles is altered, NO is increased, and NA is decreased in mesenteric PVAT. All these changes were reversed by BBR, suggesting a novel effect of BBR in ameliorating mesenteric vascular dysfunction by regulating PVAT.

Background Berberine has been found to have anti-obesity effects, and obesity can lead to adipose tissue degeneration. As a special adipose tissue, perivascular adipose tissue (PVAT) is closely related to vascular function. What happens to PVAT in diet-induced obesity and how it affects vascular function are the focus of our experimental study. Methods Sprague-Dawley rats were fed with high fat diet (fat 34% kcal) for 4 weeks, simulated early obesity model. Obesity rats were treated with BBR (200 mg/kg) or metformin (100 mg/kg) by gavage for 2 weeks. The mesenteric arterioles were studied by atomic force microscopy (AFM), the Force vs time curves were observed and analyzed to indicate vascular function. Nitric oxide (NO) and noradrenaline (NA) released were quantified using organ bath with fluorescence assays and ELISA, respectively. Using network pharmacology to analyze the overlapping targets related of BBR and obesity-related diseases, and further analyzes the expression of NOS in mesenteric perivascular adipose tissue (PVAT) with immunohistochemistry and real-time PCR. The serum inflammatory factors levels were tested. Results BBR could significantly reduce the levels of blood glucose, blood lipid and inflammatory factors in serum, and effectively improved the abnormal mesenteric vasoconstriction and relaxation in obesity rats. There was no significant change in mesenteric vascular structure in obesity rats, but collagen fibers in mesenteric tissue were increased, and NO production and eNOS expression in mesenteric PVAT were increase, NA was decrease. All these changes in obesity rats on mesenteric tissue and PVAT were reversed by treated with BBR and metformin. Conclusions In diet-induced obesity rats, the function of vasoconstriction and relaxation in mesenteric arterioles are altered, NO is increased but NA is decreased in mesenteric PVAT. All these changes are reversed by BBR, suggesting a novel effects of BBR ameliorate mesenteric vascular dysfunction through regulating the PVAT, which may closely relate with anti-inflammatory and against oxidative stress effects.